Turbo conversion


Torque Junkie
UK, Nuneaton
Probe 2.5L 24v V6
Here's some pics of the setup I've got for my Probe.




I don't have the turbo unit fitted here as I bought the setup minus the turbo unit - I want to fit a new unit just for my own piece of mind. I do, however, have the front exit Powerflow exhaust.

The turbo unit in the pic is a T70 which I gather is capable of running somewhere in the region of 600 or so bhp.

I'm not looking to run anywhere near that much, more like 250-300 to start with, and see how that goes. Should be fine with the stock injectors.

The wastegate currently has a 4psi spring fitted which should be good enough to begin with.

I still need to sort out the intercooler and piping, an oil feed kit too, and uprated fuel pump.

I'll be fitting megasquirt before I refit the interior ready for the turbo conversion, and also looking to upgrade the braking system too.
I dont want to sound negative but I think you need to do some more research on turbos.

Unfortunately you cant just bolt a large turbo on and run without lots of supporting mods.
Turbos dont work well that way. You will need a new map for a start

You also want a turbo that will be running at or near its optimim efficiency and if you are not going to fit larger injectors this will never happen with a t70
No, mate, I'm gonna need all the help I can get, so fire away, any help appreciated.

That setup came off a Probe in the first place, which is why I had it, as opposed to trying to start from scratch.

The main reason I had it was the manifolds, as most of the aftermarket kits you can get are not aligned properly and seem to end up needing rewelding anyway. I know that setup will bolt up ok. On top of that try getting anything for the Probe from the UK.

I know it's going to take a lot of work, and as for maps, the stock ECU is going and she's going to be megasquirted anyway.

I don't know loads about them in all fairness, so you're right, I still need to do a lot of reading and research.

I do know the car this came off, and the guy who still has it, so I can always check back as to what he was running with as regards injectors, etc. If needs be I can always fit bigger injectors.
In the picture the turbo looks much higher than the manifolds, will it fit under the bonnet?
Ok some basic tips on turbos

Turbos can and do provide extra power for on the face of it pretty much nothing other than bolting one on (or changing the current turbo )

Of course its not that simple - if it were every boy racer would have one.

They force more fuel/air mixture into the engine hence more power BUT you need to have that extra fuel and air available otherwise its just a waste of time.
Air isnt really a problem but fuel is.
As your engine uses injectors their size will determine how much fuel you can deliver and therefore how much power is possible Nothing you do elswhere will change this.

Most engines dont normally have a huge amount of "reserve" with the standard injectors
Now I dont know how much a v6 probe produces as std but at a guess maybe 160-180.
Lets say its 200

Going to 250 is a huge jump (25%) let alone 300 so your injector size will need to go up a similar amount to make sure they dont max out. Then you will get too lean a mixture which can be terminal

As far as turbo choice goes the most common mistake is to put a turbo on thats bigger than you need.
The bigger the turbo the more air needed to spool it up to its operating envelope but the more power it will produce ( subject to the above fuel issue being solved)
Its quantity of air that does this and this is determined by the size of the engine and the revs. A v6 2.5 engine will spool a turbo up loads quicker than a 4 cyl 2 litre.
The time it takes to reach this is the lag that is the bain of turbo engines

First thing you want is the turbos compressor map to check its compatible with your engine This will tell you what power can be produced and when it will happen

Other things you need to watch
Your engine has to be able to rev to the range that the turbo will require
Turbos produce a lot of heat check your engine is ok with this
Check your compression ratio isnt too high and that your engine can handle the extra power.
You may need different cams and/or to retard the ignition to get the best results - an aftermarket ecu will do this ( as well as provide the fuel map)

But Most Important
Speak to a tuner who has fitted turbos to your engine successfully (preferably the one you intend to use) as all the above will be documented .

This is not to say you have a bad idea - far from it but sorting the above at the beginning may well save a lot of time and money in the long run.

Finally I could be wrong but my gut feeling is that a turbo capable of 600 is way too big for a standard probe engine

Good luck
In the picture the turbo looks much higher than the manifolds, will it fit under the bonnet?

Oh yes, here's a pic of that setup fitted to a Probe :-


This is where it came from originally.

The battery does have to be relocated to the boot though as the turbo sits exactly where the battery was.

Thanks for the info, like I said, any help is much appreciated.

My car has the KLDE engine which has a 9.2:1 compression ratio. Standard is 164hp @ 5600rpm and 160ft/lbs @ 4800rpm.

There is a KLZE version for the Jap market which has a higher compression of 10:1, produces more power (200hp), but has been proven to blow head gaskets when turbo/supercharged.

I had considered going for lower compression pistons, stronger rods, etc. but unsure as to this yet.

Do you know of any good sites/resources I can look at?
Sorry but dont really get specifically involved with fords .

Your best bet is probably a probe forum - there must be one
Sorry but dont really get specifically involved with fords .

Your best bet is probably a probe forum - there must be one

Oh yes, there's three main Probe sites in the UK.

I'm a member of all three, Admin on one, active on another, and not really active on the other for various reasons.

I'm also a member of a couple of the American Probe clubs too, seeing as that's where the Probe originates, seemed like a good idea, but there are differences between the American and the UK versions.

They are useful for Probe stuff, but you don't really learn anything about other cars which is why I'm here.

I just wanted to see what others are upto, and this site is great as it covers everthing :D
Ok, so the standard injectors are 220's, the Millenia injectors are 280 and a direct fit into the same fuel rail and are supposedly good for upto 5psi boost, however I don't want to run them at 100 duty cycle, so having a 4psi spring should be ok.
I think you'd be daft not to lower the compression, it will reduce the risk of detonation and allow you to run a higher boost pressure.

Forged parts would also be a good idea if you are wanting reliability.

The big issue you will face I imagine is getting the mapping done. Do you have someone in mind who can do this for you?
I know a few people who have their Probe's running Megasquirt, so I'll be asking them where's best to go to get it tuned up once all the mods are done.

I'll be ditching the VRIS on the manifold, the VAF, dizzy, etc. and looking for an EDIS 6 setup - no more dizzy failures which plague the Probe.

I've been reading about lower compression vs higher compression with much interest. Everyone I know who has boosted a KLDE engine with 9.2:1 compression ratio, have not reduced compression, and are just running standard pistons, etc., although I know the higer compression (10:1) KLZE engine will easily blow gaskets.

In preference, I'd rather be running something like 8:1 so I'll have to see if I can get hold of some forged parts.
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